	US 12,290,425 B2
	Lint free crosslinked chitosan-PVA sponge as an absorbent wound dressing and method of preparation thereof
Lynda Velutheril Thomas, Thiruvananthapuram (IN); Prabha Damodaran Nair, Thiruvananthapuram (IN); Nimi Nirmala, Thiruvananthapuram (IN); and Shanti Krishna Ayilliath, Thiruvananthapuram (IN)
Assigned to Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thirunananthapuram (IN)
Appl. No. 16/959,143
Filed by Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thirunananthapuram (IN)
PCT Filed Dec. 26, 2018, PCT No. PCT/IN2018/050879 § 371(c)(1), (2) Date Dec. 22, 2020, PCT Pub. No. WO2019/130348, PCT Pub. Date Jul. 4, 2019.
Claims priority of application No. 201741047245 (IN), filed on Dec. 29, 2017.
Prior Publication US 2021/0322225 A1, Oct. 21, 2021
Int. Cl. A61F 13/00 (2024.01); A61F 13/01 (2024.01); C08J 3/12 (2006.01); C08J 3/18 (2006.01); C08K 5/00 (2006.01); C08L 5/08 (2006.01); C08L 29/04 (2006.01)

CPC A61F 13/01012 (2024.01) [A61F 13/01017 (2024.01); C08J 3/122 (2013.01); C08J 3/18 (2013.01); C08K 5/0016 (2013.01); C08L 5/08 (2013.01); C08L 29/04 (2013.01); A61F 2013/00348 (2013.01); C08L 2312/00 (2013.01)]

5 Claims

1. A process for the preparation of a cellular structured wound dressing consisting of the steps of:

preparing an aqueous solution of polyvinyl alcohol (PVA) and preparing a solution of a biopolymer in acid/water mixture, followed by mixing the PVA solution with the biopolymer solution to obtain a blend,

adding a plasticizer to the blend followed by adding a crosslinking agent and thoroughly mixing the same to obtain a final solution,

subjecting said final solution to lyophilization to obtain a sponge,

wherein lyophilization involves a step of freezing the blend in a range of −20° C. to −30° C. followed by drying with a temperature ramping at a rate of 4° C./min up to 40° C. to obtain cellular structured wound dressings; wherein the biopolymer is a chitosan having viscosity in the range from 200 to 2000CPS;

the crosslinking agent is a salt of borate or polyphosphates or sulphates or sulphites or citric acid or a mixture thereof; and

the plasticizer is glycerol;

wherein the cellular structured wound dressing is with a density ranging from 0.5 g/cm³to 6 g/cm³.